Reverse Selective Deposition

ABSTRACT

Methods for selectively depositing on non-metallic surfaces are disclosed. Some embodiments of the disclosure utilize a blocking compound to form a blocking layer on metallic surfaces. Deposition is performed to selectively deposit on the unblocked non-metallic surfaces. Some embodiments of the disclosure relate to methods of forming metallic vias with decreased resistance. Some embodiments utilize an unsaturated hydrocarbon as a blocking compound. Some embodiments utilize a triazole as a blocking compound.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/865,665, filed Jun. 24, 2019 and U.S. Provisional Application No.62/864,557, filed May 5, 2019, the entire disclosure of which is herebyincorporated by reference herein.

TECHNICAL FIELD

Embodiments of the disclosure generally relate to methods of reverseselective deposition. More particularly, some embodiments of thedisclosure are directed to methods of selective deposition onnon-metallic surfaces using blocking compounds comprising a triazole.More particularly, some embodiments of the disclosure are directed tomethods of selective deposition on non-metallic surfaces using blockingcompounds comprising an unsaturated hydrocarbon.

BACKGROUND

In middle of the line (MOL) and back end of the line (BEOL) structures,barrier films are typically used between metal lines and dielectriclayers to prevent diffusion and other adverse interactions between thedielectric and the metal lines. Yet the largest contribution to viaresistance is mainly due to barrier films with high resistivity.

Current approaches have focused on reducing the barrier film thicknessor finding barrier films with lower resistivity to decrease viaresistance. However, increased via resistance as a result of barrierfilms remains an issue.

One novel approach has been to block or decrease the thickness of thebarrier film on the metal surface at the bottom of the via while thethickness on the dielectric surface at the sidewalls remains. Since thebarrier properties of the barrier film are required between the metaland the dielectric, this approach allows for the barrier film to remainintact, but the reduced thickness on the metal surface improves viaresistance. These processes are referred to as selective depositionprocesses.

Selective deposition of materials can be accomplished in a variety ofways. A chemical precursor may react selectively with one surfacerelative to another surface (metallic or dielectric). Process parameterssuch as pressure, substrate temperature, precursor partial pressures,and/or gas flows might be modulated to modulate the chemical kinetics ofa particular surface reaction. Another possible scheme involves surfacepretreatments that can be used to activate or deactivate a surface ofinterest to an incoming film deposition precursor.

Accordingly, methods which allow for selective deposition onnon-metallic (e.g. dielectric) surfaces are needed.

SUMMARY

One or more embodiments of the disclosure are directed to a method offorming a blocking layer. The method comprises exposing a substrate to ablocking compound to selectively form a blocking layer on a firstsurface over a second surface. The substrate comprises a metallicmaterial having the first surface and a non-metallic material having thesecond surface

Additional embodiments of this disclosure relate to a method ofselective deposition. The method comprises exposing a substratecomprising a metallic material having a first surface and a non-metallicmaterial having a second surface to a triazole to selectively form ablocking layer on the first surface over the second surface. Thesubstrate is sequentially exposed to a metal precursor and a reactant toform a film on the second surface over the blocking layer on the firstsurface. The blocking layer is removed from the first surface.

Further embodiments of this disclosure relate to a method of forminglow-resistance metal vias. The method comprises providing a substratehaving a substrate surface with at least one feature formed therein. Theat least one feature has a sidewall and a bottom. The sidewall comprisesa non-metallic material surface. The bottom comprises a metallicmaterial surface. The substrate is exposed to a triazole to selectivelyform a blocking layer on the metallic material surface over thenon-metallic material surface. The substrate is sequentially exposed toa metal precursor and a reactant to form a film on the non-metallicmaterial surface over the blocking layer on the metallic materialsurface. The blocking layer is optionally removed from the metallicmaterial surface. A conductive fill material is deposited within the atleast one feature to form a low-resistance metal via.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIG. 1 illustrates a cross-sectional view of an exemplary substrateduring processing according to one or more embodiment of the disclosure;and

FIG. 2 illustrates a cross-sectional view of an exemplary substrateduring processing according to one or more embodiment of the disclosure.

In the appended figures, similar components and/or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If only the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

DETAILED DESCRIPTION

Before describing several exemplary embodiments of the disclosure, it isto be understood that the disclosure is not limited to the details ofconstruction or process steps set forth in the following description.The disclosure is capable of other embodiments and of being practiced orbeing carried out in various ways.

As used in this specification and the appended claims, the term“substrate” refers to a surface, or portion of a surface, upon which aprocess acts. It will also be understood by those skilled in the artthat reference to a substrate can also refer to only a portion of thesubstrate, unless the context clearly indicates otherwise. Additionally,reference to depositing on a substrate can mean both a bare substrateand a substrate with one or more films or features deposited or formedthereon

A “substrate” as used herein, refers to any substrate or materialsurface formed on a substrate upon which film processing is performedduring a fabrication process. For example, a substrate surface on whichprocessing can be performed include materials such as silicon, siliconoxide, strained silicon, silicon on insulator (SOI), carbon dopedsilicon oxides, amorphous silicon, doped silicon, germanium, galliumarsenide, glass, sapphire, and any other materials such as metals, metalnitrides, metal alloys, and other conductive materials, depending on theapplication. Substrates include, without limitation, semiconductorwafers. Substrates may be exposed to a pretreatment process to polish,etch, reduce, oxidize, hydroxylate, anneal, UV cure, e-beam cure and/orbake the substrate surface. In addition to film processing directly onthe surface of the substrate itself, in the present disclosure, any ofthe film processing steps disclosed may also be performed on anunderlayer formed on the substrate as disclosed in more detail below,and the term “substrate surface” is intended to include such underlayeras the context indicates. Thus for example, where a film/layer orpartial film/layer has been deposited onto a substrate surface, theexposed surface of the newly deposited film/layer becomes the substratesurface.

Embodiments of the present disclosure relate to methods for selectivelyforming a blocking layer on a metallic material surface. Someembodiments of the present disclosure further relate to methods forselectively depositing a film on a non-metallic material surface over ametallic material surface. Some embodiments of the present disclosurefurther relate to methods for forming metal vias with lower resistance.

Some embodiments of the disclosure advantageously provide methods forselectively forming a blocking layer on a metallic material surface.

As used in this specification and the appended claims, the phase“metallic material surface” or “non-metallic material surface” refers tothe surface of a metallic or non-metallic material, respectively. Insome embodiments, the non-metallic material is a dielectric material.

As used in this specification and the appended claims, the term“selectively depositing on a first surface over a second surface”, andthe like, means that a first amount or thickness is deposited on thefirst surface and a second amount or thickness is deposited on thesecond surface, where the second amount or thickness is less than thefirst amount or thickness, or, in some embodiments, no amount isdeposited on the second surface.

As used in this regard, the term “over” does not imply a physicalorientation of one surface on top of another surface, rather arelationship of the thermodynamic or kinetic properties of the chemicalreaction with one surface relative to the other surface. For example,selectively depositing a cobalt film onto a copper surface over adielectric surface means that the cobalt film deposits on the coppersurface and less or no cobalt film deposits on the dielectric surface;or that the formation of the cobalt film on the copper surface isthermodynamically or kinetically favorable relative to the formation ofa cobalt film on the dielectric surface.

In some embodiments, “selectively” means that the subject material formson the selected surface at a rate greater than or equal to about 2×, 3×,4×, 5×, 7×, 10×, 15×, 20×, 25×, 30×, 35×, 40×, 45× or 50× the rate offormation on the non-selected surface. Stated differently, theselectivity of the stated process for the selected surface relative tothe non-selected surface is greater than or equal to about 2:1, 3:1,4:1, 5:1, 7:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1 or 50:1.

One or more embodiments of this disclosure are directed to methods ofselectively forming a blocking layer on a first surface of a substrateover a second surface. The substrate comprises a metallic material witha first surface and a non-metallic material with a second surface. Insome embodiments, the first surface may be described as a metallicmaterial surface and the second surface may be described as anon-metallic material surface.

The metallic material of the substrate may be any suitable metallicmaterial. In some embodiments, the metallic materials of this disclosureare conductive materials. Suitable metallic materials include, but arenot limited to, metals, metal nitrides, some metal oxides, metal alloys,silicon, combinations thereof and other conductive materials.

In some embodiments, the metallic material comprises chromium,manganese, iron, copper, nickel, cobalt, tungsten, ruthenium,molybdenum, tantalum, titanium or combinations thereof. In someembodiments, the metallic material consists essentially of chromium,manganese, iron, copper, nickel, cobalt, tungsten, ruthenium,molybdenum, tantalum oxide, tantalum nitride, titanium oxide or titaniumnitride. In some embodiments, the metallic material consists essentiallyof one or more of copper, cobalt, ruthenium, tungsten and molybdenum. Insome embodiments, the metallic material comprises or consistsessentially of silicon. As used in this specification and the appendedclaims, the term “consists essentially of” means that the material isgreater than or equal to about 95%, 98% or 99% of the stated material onan atomic basis.

As used in this specification and the appended claims, the term “oxide”or the like means that the material contains the specified element(s).The term should not be interpreted to imply a specific ratio ofelements. Accordingly, an “oxide” or the like may comprise astoichiometric ratio of elements or a non-stoichiometric ratio ofelements.

The non-metallic material of the substrate may be any suitable material.In some embodiments, the non-metallic materials of this disclosure aredielectric materials. Suitable non-metallic materials include, but arenot limited to, silicon oxides (e.g. SiO₂), silicon nitrides, siliconcarbides and combinations thereof (e.g. SiCON). In some embodiments, thenon-metallic material consists essentially of silicon dioxide (SiO₂). Insome embodiments, the non-metallic material comprises silicon nitride.In some embodiments, the non-metallic material consists essentially ofsilicon nitride.

Referring to FIG. 1, an exemplary method 100 begins with a substrate 105comprising a metallic material 110 having a first surface 112 and anon-metallic material 120 having a second surface 122. The substrate 105is exposed to a blocking compound (not shown) to selectively form ablocking layer 130 on the first surface 112 over the second surface 122.In some embodiments, the surface of the blocking layer is described as ablocked first surface 132.

In some embodiments, the first surface 112 is cleaned prior to exposureto the blocking compound. The first surface may be cleaned by anysuitable method including, but not limited to, a hydrogen thermalanneal, an ethanol clean, or a plasma hydrogen clean.

In some embodiments, the blocking compound comprises an unsaturatedhydrocarbon. Without being bound by theory, it is believed that the dorbitals of the metallic materials start to share electrons with the sp²orbitals of the unsaturated hydrocarbon.

Accordingly, in some embodiments, the unsaturated hydrocarbon comprisesat least one compound with at least one double bond between two carbonatoms. Stated differently, in some embodiments, the unsaturatedhydrocarbon comprises at least one compound with a general formula ofR′═R″. In some embodiments, the unsaturated hydrocarbon comprises atleast one compound with at least one triple bond between two carbonatoms. Stated differently, in some embodiments, the unsaturatedhydrocarbon comprises at least one compound with a general formula ofR′≡R″.

In some embodiments, the compound of the unsaturated hydrocarboncontains only one unsaturated bond. Without being bound by theory, it isbelieved that multiple unsaturated bonds increases the likelihood ofpolymerization and increases the difficulty of removing the blockinglayer without damaging the surrounding substrate materials.

Further, without being bound by theory, it is believed that theunsaturated hydrocarbon suppresses both the nucleation and growth rateof films on the metallic material surface.

In some embodiments, R′ and R″ are identical. In some embodiments, R′and R″ are independent C2-C6 groups. As used in this regard, a “C2-C6group” contains 2-6 carbon atoms. In some embodiments, R′ and R″comprise only carbon and hydrogen atoms. In some embodiments, R′ and R″do not comprises any surface reactive moieties. In some embodiments, thecompound of the unsaturated hydrocarbon does not contain an unsaturatedbond on the terminal carbon. In some embodiments, the compound of theunsaturated hydrocarbon comprises 4-12 carbon atoms. In someembodiments, R′ and/or R″ are linear. In some embodiments, R′ and/or R″are branched.

In some embodiments, the unsaturated hydrocarbon comprises at least onecompound with a general formula of R′≡R″, an alkyne. In someembodiments, the compound of the unsaturated hydrocarbon comprises orconsists essentially of one or more of 3-hexyne, 4-octyne, 5-decyne,6-dodecyne and 7-tetradecyne.

In some embodiments of the alkyne, the triple bond attaches to aterminal carbon. Stated differently, in some embodiments, R′ or R″ is aC1 group. In some embodiments, when R′ is a C1 group, R″ is a C3-C18group. In some embodiments, the unsaturated hydrocarbon comprises orconsists essentially of one or more of 1-heptyne, 1-octyne, 1-nonyne,1-decyne, 1-undecyne, 1-dodecyne, and 1-tetradecyne.

In some embodiments, the blocking compound comprises a triazole. In someembodiments, the blocking compound comprises one or more of1,2,3-triazole, 1,2,4-triazole, benzotriazole, alkyl substituted1,2,3-triazoles and alkyl substituted benzotriazoles. As used in thisspecification and the appended claims, an alkyl substitution may includesubstitution with a C1-C4 alkyl group. The alkyl group may be linear orbranched. In some embodiments, the blocking compound consistsessentially of benzotriazole.

In some embodiments, the processing conditions for exposing thesubstrate to the blocking compound may be controlled. In someembodiments, the substrate is soaked in a vapor of the blockingcompound.

In some embodiments, the pressure of the processing chamber iscontrolled. The pressure of the processing chamber may be any suitablepressure for forming the blocking layer. In some embodiments, thepressure of the processing chamber is maintained at less than or equalto about 80 Torr, less than or equal to about 70 Torr, less than orequal to about 60 Torr, less than or equal to about 50 Torr, less thanor equal to about 40 Torr, less than or equal to about 30 Torr, lessthan or equal to about 20 Torr, less than or equal to about 15 Torr,less than or equal to about 10 Torr, or less than or equal to about 5Torr. In some embodiments, the pressure of the processing chamber ismaintained at about 10 Torr, about 20 Torr, about 30 Torr, about 40Torr, or about 50 Torr.

In some embodiments, the flow rate of the blocking compound iscontrolled. The flow rate of the blocking compound may be any suitableflow rate for forming the blocking layer. In some embodiments, the flowrate of the blocking compound is in a range of about 50 sccm to about100 sccm, or in a range of about 75 sccm to about 100 sccm. In someembodiments, the flow rate of the blocking compound is less than orequal to about 600 sccm, less than or equal to about 500 sccm, less thanor equal to about 400 sccm, less than or equal to about 300 sccm, lessthan or equal to about 250 sccm, less than or equal to about 200 sccm,less than or equal to about 150 sccm, less than or equal to about 100sccm, less than or equal to about 75 sccm, or less than or equal toabout 50 sccm. In some embodiments, the flow rate of the blockingcompound is about 50 sccm or about 100 sccm.

In some embodiments, the soak period, during which the blocking compoundis exposed to the substrate, is controlled. The soak period may be anysuitable period for forming the blocking layer. In some embodiments, thesoak period is greater than or equal to about 10 s, greater than orequal to about 20 s, greater than or equal to about 30 s, greater thanor equal to about 45 s, greater than or equal to about 60 s, greaterthan or equal to about 80 s, greater than or equal to about 120 s,greater than or equal to about 150 s, or greater than or equal to about200 s. In some embodiments, the soak period is about 60 s. In someembodiments, the soak period is about 200 s.

In some embodiments, the temperature of the substrate is controlledduring exposure to the blocking compound. In some embodiments, thetemperature of the substrate is less than or equal to about 400° C.,less than or equal to about 380° C., less than or equal to about 350°C., less than or equal to about 300° C., less than or equal to about275° C., less than or equal to about 250° C., less than or equal toabout 225° C., or less than or equal to about 200° C. In someembodiments, the temperature of the substrate is in a range of about 20°C. to about 380° C. or in a range of about 50° C. to about 400° C.

In some embodiments, the compound of the blocking compound is a liquidat the operating temperature. In some embodiments, the blocking compoundhas a vapor pressure greater than or equal to about 0.1 Torr at theexposure temperature.

In some embodiments, the method 100 continues with the deposition of afilm 115 on the second surface 122 over the blocked first surface 132(see FIG. 1C). The film 115 may be deposited by any known method.

In some embodiments, the film 115 is deposited by atomic layerdeposition. In some embodiments, the film 115 is deposited bysequentially exposing the substrate 105 to a metal precursor and areactant. In some embodiments, the film 115 comprises a metal nitride.In some embodiments, the film 115 comprises a metal oxide. In someembodiments, the film 115 comprises one or more of silicon, aluminum,titanium, tantalum, hafnium and zirconium.

In some embodiments, the film 115 functions as a barrier film, barrierlayer or diffusion layer. In some embodiments, the film 115 comprisestitanium nitride. In some embodiments, the film 115 comprises tantalumnitride. In some embodiments, the film 115 comprises aluminum oxide. Insome embodiments, the film is formed without the use of plasma.

In some embodiments, the film 115 is deposited at a temperature whichdoes not impact the stability of the blocking layer 130. In someembodiments, the film 115 is deposited at a temperature in a range ofabout 100° C. to about 380° C. or in a range of about 100° C. to about400° C.

In some embodiments, the substrate is exposed to the blocking compoundbetween ALD cycles. In some embodiments, the substrate may be re-exposedto the blocking compound after each deposition cycle. In someembodiments, the substrate may be re-exposed to the blocking compoundafter several deposition cycles.

In some embodiments, the method continues by removing the blocking layer130 from the first surface 112. The blocking layer may be removed by anysuitable means, including but not limited to, plasma cleaning processesor thermal decomposition.

In some embodiments, the substrate is exposed to a plasma to remove theblocking layer 130 from the first surface 112. In some embodiments, theplasma comprises argon (Ar), nitrogen (N₂) or hydrogen (H₂). In someembodiments, the plasma consists essentially of argon. In someembodiments, the plasma comprises a mixture of H₂/Ar. In someembodiments, the mixture of H₂/Ar is about 1:1.

The power of the plasma may be varied depending on the composition andthickness of the blocking layer and the surrounding materials. In someembodiments, the plasma power is in a range of about 50 W to about 500W, in a range of about 100 W to about 450 W, or in a range of about 200W to about 400W. In some embodiments, the plasma power is about 50 W,about 200 W or about 400 W.

The duration of the plasma exposure may be varied depending on thecomposition and thickness of the blocking layer and the surroundingmaterials. In some embodiments, the substrate is exposed to the plasmafor a period in a range of about 2 s to about 60 s, in a range of about3 s to about 30 s, or in a range of about 5 s to about 10 s. In someembodiments, the substrate is exposed to the plasma for a period ofabout 3 s, about 5 s, about 10 s or about 30 s.

In some embodiments, the substrate is exposed to an elevated temperatureto remove the blocking layer 130 from the first surface 112. In someembodiments, the elevated temperature is greater than or equal to about300° C., greater than or equal to about 320° C., greater than or equalto about 325° C., greater than or equal to about 330° C., greater thanor equal to about 350° C., greater than or equal to about 380° C., orgreater than or equal to about 400° C.

Referring to FIG. 2, an exemplary method 200 begins by providing asubstrate 210 having a substrate surface 205 with at least one feature220 formed therein. The at least one feature 220 has sidewalls 222, 224and a bottom 228. The sidewalls 222, 224 comprise a non-metallicmaterial 230 surface. The bottom 228 comprises a metallic material 240surface.

The method 200 continues by exposing the substrate 210 to a blockingcompound (not shown) to selectively form a blocking layer 250 on themetallic material 240 surface on the bottom 228 of the feature 220 overthe non-metallic material 230 surface on the sidewalls 222, 224.

The method 200 continues by depositing a film 260 on the non-metallicmaterial 230 surface on the sidewalls 222, 224 of the feature 220 overthe blocking layer 250. In some embodiments, the film 260 is depositedby sequentially exposing the substrate 210 to a metal precursor and areactant.

The method 200 includes optionally removing the blocking layer 250 fromthe metallic material 240 surface on the bottom 228 of the feature 220.FIG. 2 shows the substrate 210 after the blocking layer 250 is removedaccording to some embodiments.

Without being bound by theory, it is believed that the blocking layerincreases the resistance of the metal via only marginally when comparedto the increase in resistance typically seen with most barrier layers(e.g. film 260). Accordingly, the removal of the blocking layer is anoptional process which may further decrease the resistance of the metalvia.

Referring to FIG. 2, the method 200 continues by depositing a conductivefill material 270 within the at least one feature 220 to form alow-resistance metal via. In some embodiments, the low-resistance metalvia has a resistance less than or equal to about 80% of a metal viaformed without the blocking layer. Stated differently, thelow-resistance metal vias formed by the disclosed process including theblocking layer 250 provide a via resistance reduction of greater than orequal to about 20%.

Reference throughout this specification to “one embodiment,” “certainembodiments,” “one or more embodiments” or “an embodiment” means that aparticular feature, structure, material, or characteristic described inconnection with the embodiment is included in at least one embodiment ofthe disclosure. Thus, the appearances of the phrases such as “in one ormore embodiments,” “in certain embodiments,” “in one embodiment” or “inan embodiment” in various places throughout this specification are notnecessarily referring to the same embodiment of the disclosure.Furthermore, the particular features, structures, materials, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

Although the disclosure herein has been described with reference toparticular embodiments, those skilled in the art will understand thatthe embodiments described are merely illustrative of the principles andapplications of the present disclosure. It will be apparent to thoseskilled in the art that various modifications and variations can be madeto the method and apparatus of the present disclosure without departingfrom the spirit and scope of the disclosure. Thus, the presentdisclosure can include modifications and variations that are within thescope of the appended claims and their equivalents.

1. A method of forming a blocking layer, the method comprising exposinga substrate comprising a metallic material having a first surface and anon-metallic material having a second surface to a blocking compound toselectively form a blocking layer on the first surface over the secondsurface, wherein the blocking compound comprises a triazole.
 2. Themethod of claim 1, wherein the blocking compound further comprises anunsaturated hydrocarbon with a general formula R′≡R″.
 3. The method ofclaim 2, wherein the unsaturated hydrocarbon contains only one triplebond.
 4. The method of claim 3, wherein the unsaturated hydrocarboncomprises 3-hexyne.
 5. The method of claim 2, wherein R′ is a C1 group.6. The method of claim 5, wherein R″ is a C3-C18 group.
 7. The method ofclaim 1, wherein the triazole comprises one or more of 1,2,3-triazole,1,2,4-triazole, benzotriazole, an alkyl substituted 1,2,3-triazole andan alkyl substituted benzotriazole.
 8. The method of claim 7, whereinthe triazole consists essentially of benzotriazole.
 9. The method ofclaim 1, wherein the metallic material comprises one or more of copper,cobalt, tungsten, molybdenum or ruthenium.
 10. The method of claim 1,wherein the non-metallic material comprises silicon oxide.
 11. Themethod of claim 1, further comprising selectively depositing a film onthe second surface over the blocked first surface.
 12. The method ofclaim 10, wherein the film is deposited by sequentially exposing thesubstrate to a metal precursor and a reactant.
 13. The method of claim1, further comprising exposing the substrate to an elevated temperatureto remove the blocking layer.
 14. The method of claim 13, wherein theelevated temperature is greater than or equal to about 330° C.
 15. Amethod of selective deposition, the method comprising: exposing asubstrate comprising a metallic material having a first surface and anon-metallic material having a second surface to a triazole toselectively form a blocking layer on the first surface over the secondsurface; and sequentially exposing the substrate to a metal precursorand a reactant to form a film on the second surface over the blockinglayer on the first surface; and removing the blocking layer from thefirst surface.
 16. The method of claim 15, wherein the triazolecomprises benzotriazole.
 17. A method of forming low-resistance metalvias, the method comprising: providing a substrate having a substratesurface with at least one feature formed therein, the at least onefeature having a sidewall and a bottom, the sidewall comprising anon-metallic material surface, the bottom comprising a metallic materialsurface; exposing the substrate to a triazole to selectively form ablocking layer on the metallic material surface over the non-metallicmaterial surface; sequentially exposing the substrate to a metalprecursor and a reactant to form a film on the non-metallic materialsurface over the blocking layer on the metallic material surface;optionally removing the blocking layer from the metallic materialsurface; and depositing a conductive fill material within the at leastone feature to form a low-resistance metal via.
 18. The method of claim17, wherein the triazole comprises benzotriazole.
 19. The method ofclaim 17, wherein the film comprises aluminum oxide.
 20. The method ofclaim 17, wherein the low-resistance metal via has a resistance lessthan or equal to about 80% of a metal via formed without a blockinglayer.